1. Field
The present invention relates generally to heat dissipation devices for removing heat from heat-generating devices such as electronic packages, and particularly to a heat dissipation device having improved structure for mounting an electric fan to a heat sink of the heat dissipating device.
2. Prior Art
As the electronics technology advances rapidly, electronic packages are able to process at a high speed. As a result, such electronic packages generate substantial amounts of heat. The heat must be removed from the electronic packages efficiently; otherwise, the electronic packages would malfunction. Thus, heat dissipation devices are attached to electronic packages to remove heat therefrom.
FIG. 4 shows a conventional heat dissipation device 5, which comprises a heat sink 51 including a plurality of space apart fins 511, a fan mounting structure 52 comprising a pair of fan fasteners 521. Each fan fastener 521 includes an upper plate 5211 where an electric fan 53 seats and a lower plate 5212 for attaching to one of two opposite lateral sides of the heat sink 51 by inserting the lower plate 5212 into a groove (not labeled) defined in a corresponding lateral side of the heat sink 51. The fan 53 is mounted to the fan mounting structure 52, particularly to the upper plates 5211. The heat dissipation device 5 further comprises a plurality of fixing devices 54 securing the fan 53 to the fan mounting structure 52. FIG. 5 demonstrates the assembled conventional heat dissipation device which shows that the fixing devices 54 extend through the fan 53 and the upper plates 5211 and engage with the fins 511.
However, the conventional heat dissipation device 5 has several drawbacks. The first drawback of the conventional heat dissipation device 5 is that during the process of fastening the fixing devices 54, the fixing devices 54 might deform the fins 511. The deformation of the fins 511 may damage the fins 511 and affect the heat dissipating effectiveness of the fins 511. Therefore, the heat dissipation efficiency of the heat dissipation device 5 is lowered. The fan mounting structure 52 relies on the lower plates 5212 inserted into the grooves to secure on the heat sink 51; however, the weak structure of the lower plates 5212 can be deformed during the assembly and unable to secure the fan mounting structure 52 to the heat sink 51. Once the lower plates 5212 are deformed, the fan 53 can not be seated on the fan mounting structure 52 securely and the fan 53 gains a space to vibrate when it is activated; thus noise is created when the fan 53 is activated. Moreover, the lower plate 5212 only engages in the corresponding groove with a part of a length of the groove; such a partial engagement between the lower plate 5212 and the groove can not ensure a sufficient connection between the lower plate 5212 and the heat sink 51, and thereby, the fan fastener 521 is possible to separate from the heat sink 51 by the vibration of the fan 53. Finally, each of the upper plate 5211 is consisted of a single layer which is a weak structure and has the drawback of unable to hold the fan stably for a long period. The fan 53 generally vibrates when it's activated. The vibration of the fan 53 would exert a large force on the upper plate 5211 which would deform the upper plate 5211 and hence gain a space between the upper plate 5211 and the fan 53. As the result, noise would be created when the fan 53 is activated and vibrates. Furthermore, the engagement of the fixing devices 54 with the single-layer upper plates 5211 may be loosen due to the vibration of the activated fan 53. Such a conventional heat dissipation device 5 is disclosed in U.S. Pat. No. 6,816,373.
Therefore, a novel design of a heat dissipation device is desired to overcome the aforementioned drawbacks, and increase the heat dissipation effect thereof.